Ok I must admit that I asked for trouble by not mentioning that I don`t have a picturesque scenery before and after comparison samples but here you go:
Crappy before and after samples

Notice that it was taken with the lens wide open and AF focusing on I don`t know what :)...
The vignetting can not be seen on TV or camcorders LCD I guess I`ll modyfy the lens by removing those unusable filter threads so it will not vignette.
CA is due the camcorders own lens as you might notice and considering that original lens barrel too my estimate is that it doesn`t barrel that much.

Hope that helps a little, I`ll try to get some "beauty" shots soon enough.

Thanks for the images. It looks like it does give a little curve distortion to the outer edges of the footage....This effect is what I want. When you get a chance some outdoor images would be nice to really determine how it looks. I don't mind that tiny vigenette. I can deal with that easy enough.

Toenis, it looks to me as if your lens manufacturer has inadvertently (ha!) misrepresented a 0.7x converter and labelled it as a 0.45x - not uncommon with what I'll call 'no-name' brands. Once you've zoomed up to remove the vignetting (which you'll need to do for any film that'll be projected or shown on google video, for instance) you'll be down to a very mild 0.8x.

The vignetting will be down to the entry pupil's diameter and the distance it's from your zoom's front element, so 'removing threads' won't help. You haven't got a filter between converter lens and zoom, have you?

Ok, the lens looks pretty flare free and the image is sharp enough, but a genuine 0.45x should more than halve your focal length and in so doing give you dramatically wider footage.

I like the Canon wide angle lense alot. It changes the camera balance alot and is a bit of a pain to stow if you have a small camera bag. I have produced great images with it. I have not read of anyone with a better alternative than this lense.

One of my lenses was actually for the XL1 I believe. They do fit if they are bayonet mount, it is just a very odd fit. I played with it for five minutes and was just about to give up then it just slipped on and the resolution was good in HD too. Problem is, I couldnt figure out a reliable way to get it on but both the WA and fisheye went on with some time spent. No forcing it was needed, just wiggling.